Digital Audio
Delta-Sigma is a method of analogue-to-digital (ADC) and digital-to-analogue (DAC) conversion that achieves high resolution and accuracy by oversampling the input signal and using noise shaping to push quantisation noise outside the audible frequency range.
In a Delta-Sigma converter, the analogue signal is sampled at a rate many times higher than the target audio bandwidth. The delta (difference) component measures the change between successive samples, while the sigma (sum) component integrates these differences to reconstruct the waveform digitally. This process allows the converter to achieve very fine resolution with fewer bits per sample, which are then averaged through digital filtering to produce a high-precision result.
The technique became widely adopted in digital audio equipment during the late 1980s and 1990s, replacing earlier multi-bit ladder converters. It offers excellent linearity, low distortion, and high dynamic range, making it standard in modern CD players, DACs, audio interfaces, and professional converters. Delta-Sigma conversion continues to be refined through advancements in oversampling rates, filter design, and modulation schemes, ensuring superior accuracy and transparency in digital audio reproduction.
